Dirt separator for compressor diffuser in gas turbine engine

ABSTRACT

A compressor diffuser for a gas turbine engine is provided with a dirt separator. The dirt separator ensures the air having moved downstream of the compressor section, and moving toward the combustion section, is separated into a dirtier air flow path directly radially outwardly, and a cleaner airflow path directed radially inwardly. In this manner, the air reaching a combustion section, and the air being utilized for radially inner cooling air is relatively cleaner air. Further, the dirt separator provides a convenient surface for mounting a pressure sensor. In one embodiment, the dirt separator is mounted within the diffuser housing, and in a second embodiment, it is mounted immediately downstream.

BACKGROUND OF THE INVENTION

This application relates to the association of a dirt separator with acompressor diffuser for a gas turbine engine.

Gas turbine engines are provided with a number of functional sections,including a fan section, a compressor section, a combustion section, anda turbine section. Air and fuel are combusted in the combustion section.The products of the combustion move downstream, and pass over a seriesof turbine rotors, driving the rotors to power the compressors of thecompressor section.

Numerous components within the gas turbine engine are subject to highlevels of heat during operation. As an example, a turbine rotor willhave a plurality of turbine blades that are driven by high temperatureproducts of combustion to rotate and create the power. Cooling fluid,and typically air, is passed within a body of the turbine blades to coolthe turbine blades. Air is also necessary for combustion.

The air passing through a gas turbine engine is often subjected to dirtand other impurities. It is desirable that the air utilized for coolingvarious components be relatively clean. The cooling of the componentsmay be through relatively small passages, and the dirt and impuritiescan clog those small passages. The air passing from the compressorsection passes through a diffuser. Directly downstream of the diffuseris the combustion section. It would be desirable for the air reachingthe combustion section and being used for cooling to be as clean aspossible.

The present invention is directed to separating dirtier air from cleanerair in the diffuser. This minimizes the amount of dirty air passingthrough the combustion section, and being used for cooling functions.

SUMMARY OF THE INVENTION

In the disclosed embodiment of this invention, a dirt separator issecured downstream of a compressor and upstream of a combustion sectionin a gas turbine engine. In one embodiment, the dirt separator ismounted within a compressor diffuser, and in a second embodiment, thedirt separator is mounted immediately downstream of the compressordiffuser. The dirt separator is configured such that it directsrelatively dirty air downstream to radially outermost passages withinthe gas turbine engine. The air delivered to radially inner locationsfor cooling purposes, and into the combustion section is largely cleanerair, which is directed radially inwardly by the dirt separator. In adisclosed embodiment the dirt separator has curved surfaces to guide thedirty air radially outwardly and to guide the cleaner air toward thecombustion section and the inner cooling passages.

In another feature, the dirt separator provides a convenient locationfor mounting a pressure sensor. In the prior art, some additionalbracketing, etc., has been required to mount a pressure sensor at alocation directly downstream of the compressor diffuser. The presentinvention thus provides a simple arrangement for mounting the sensor.

These and other features of the present invention can be best understoodfrom the following specification and drawings, the following of which isa brief description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a highly schematic view of a gas turbine engine.

FIG. 1B is a view of a portion of the prior art gas turbine engine.

FIG. 2A is a view similar to FIG. 1B but showing the inventivecompressor diffuser.

FIG. 2B shows an enlarged view of a portion of the FIG. 2A dirtseparator.

FIG. 3 shows another embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1A shows a gas turbine engine 10. As known, a fan section 11 movesair and rotates about an axial center line 12. A compressor section 13,a combustion section 14, and a turbine section 15 are also centered onthe axial center line 12. FIG. 1A is a highly schematic view, however,it does show the main components of the gas turbine engine. Further,while a particular type of gas turbine engine is illustrated in thisfigure, it should be understood that the present invention extends toother types of gas turbine engines.

The turbine section 15 includes a rotor having turbine blades 20, andstationary vanes 18. As mentioned above, these turbine blades 20 andvanes 18 become quite hot as the products of combustion pass over themto create power. Various cooling schemes are utilized for cooling thesecomponents.

FIG. 1B focuses on a location intermediate the compressor section 13 andthe beginning of the combustion section 14. As is known, a compressordiffuser 120 is positioned in this location to expand the flow of theair having passed through the compressor section 13. An inlet 22 has asmaller cross-sectional area than an outlet 24. A chamber 26 downstreamof the diffuser 120 leads air into the combustion section 14 and bothradially inwardly and radially outwardly of the combustion section wherethe air provides various cooling functions, such as at the turbinesection.

In the prior art, the air leaving the compressor section 13 may berelatively dirty. When this dirty air reaches the combustion section 14,it can cause undesirable consequences. That is, the air moving withinthe combustion section to be mixed with fuel and burned contains dirtyair. As an example, the dirt can clause glassy plasma deposits on burnerliners and shorten the life of the liners. Further, as mentioned above,when this dirty air is utilized as the internal cooling air flow, dirtand other impurities may clog small cooling passages, which isundesirable.

FIG. 2A shows an inventive diffuser 30 wherein the inlet 32 and theoutlet 34 function in a manner similar to the FIG. 1B embodiment.However, as is shown, a dirt separator 42 is positioned adjacent to theoutlet 34. An apex 44 on the dirt separator leads into a curved radiallyouter face 43, and a curved radially inner face 45. As can beappreciated, the curved radially outer face 43 guides the flow of air 38radially outwardly, such that it will be largely radially outward of thecombustion section 14, and pass into a radially outermost air flowchannel.

The radially inner face 45 of the dirt separator 42 is also curvedoutwardly to an outlet end 146. Thus, a flow of air 40 is directedradially inwardly to radially inner cooling air channels, and also tothe combustion section. Since the outlet end 146 does have a radiallyoutward component, this clean air is also guided radially outwardlytowards the combustion section 14. This flow of air 40 will tend to becleaner air than the air flow 38. Heavier dirt laden air will tend tomove radially outwardly due to centrifugal effects. Thus, the presentinvention directs cleaner air to the combustion section 14, and forinner cooling air purposes.

As can be seen in FIG. 2A, a radially outer surface 300 of the diffuser30 flares radially outwardly. This assists in guiding the air flow 38 tothe radially outer passages. Often in the prior art (see FIG. 1A), thissurface 299 was not flared radially outwardly. This feature,particularly when combined with the dirt separator 42, assists inguiding the dirtier air flow radially outwardly.

As can be appreciated from FIG. 2B, outlet end 146 of radially innerface 45 curves outwardly with a small component in a radially outwarddirection. This will serve to direct some of the cleaner air, havinginitially been separated at the apex 44, in a radially outwarddirection, and in particular to the combustion section 14. That is, thecleaner air passes to the interior of the combustion section to be mixedwith fuel and burned. Again, the air passing radially outwardly of theguide face 43 will pass radially outwardly of the combustion section.

FIG. 2B shows another feature of the present invention. A sensor 48 ismounted in an end face 46 of the dirt separator 42. The sensor 48 is apressure sensor for sensing the pressure in chamber 36, which isdirectly downstream of the diffuser 30. A control wire 50 extends to acontrol, which may be an engine control. As is known, engine controlstake any number of variables including the pressure from the chamber 36and utilize these pressures to determine how to control the engine. Byproviding a sensor mount location in dirt separator 42, the presentinvention eliminates the need for a separate mount structure.

FIG. 3 shows another embodiment, which is similar to the FIG. 2Aembodiment, however the dirt separator is mounted immediately downstreamof the diffuser housing. This embodiment includes reference numeralswhich are each 200 higher than the reference numerals of FIG. 2A, andoperates in a similar fashion to the FIG. 2A embodiment.

Although FIGS. 2A and 3 show only a single section, it should beappreciated that the diffuser and the dirt separator generally extend360° about the center axis 12 (see FIG. 1A).

As is clear from FIG. 2A, diffuser 30 has inlet 32 directly attached toa downstream end of a compressor. The diffuser outlet is spaced from aninlet of the downstream combustion section 14 such that air leaving saidoutlet may move said radially outwardly of the combustion section.

1. A compressor diffuser and dirt separator for a gas turbine enginecomprising: a diffuser housing with an inlet having a firstcross-sectional area and an outlet having a second cross-sectional area,said second cross-sectional area being greater than said firstcross-sectional area; and a dirt separator positioned near a downstreamend of said diffuser housing, and adjacent said outlet, said dirtseparator being operable to separate heavier dirt laden air to radiallyouter locations, and relatively cleaner air to radially inner locations,and such that the majority of the heavier dirt laden air, which isradially outward of said dirt separator is directed radially outwardlyof a radially outermost surface of a combustion section to be mounteddownstream of the diffuser, and such that air from a radially innermostlocation is directed toward the combustion section, and such that theair which does move into an interior of the combustion section to bemixed with fuel and burned is air from a location radially inward ofsaid dirt separator.
 2. The compressor diffuser and dirt separator asset forth in claim 1, wherein said dirt separator has a first curvedface facing radially outwardly and a second curved face facing radiallyinwardly, with said first curved face directing the dirt laden air toradially outer locations.
 3. The compressor diffuser and dirt separatoras set forth in claim 2, wherein said second curved face initiallydirects the relatively cleaner air radially inwardly, and then curvesradially outwardly to direct some air with a component of radiallyoutward movement.
 4. The compressor diffuser and dirt separator as setforth in claim 1, wherein a pressure sensor is mounted within said dirtseparator.
 5. The compressor diffuser and dirt separator as set forth inclaim 4, wherein said pressure sensor is mounted in an end face of saiddirt separator.
 6. The compressor diffuser and dirt separator as setforth in claim 1, wherein said dirt separator is positioned within saiddiffuser housing.
 7. The compressor diffuser and dirt separator as setforth in claim 1, wherein said dirt separator is positioned downstreamof said outlet of said diffuser housing.
 8. The compressor diffuser anddirt separator as set forth in claim 1, wherein a radially outer surfaceon said diffuser housing flares radially outwardly to assist in guidingthe heavier dirt-laden air to the radially outer locations.
 9. Thecompressor diffuser and dirt separator as set forth in claim 1, whereinsaid inlet for being directly attached to a downstream end of acompressor.
 10. The compressor diffuser and dirt separator as set forthin claim 9, wherein said outlet being spaced from a downstreamcombustion section such that air leaving said outlet may move saidradially outwardly of the combustion section.